[IRCA] Sony ICF-SW7600GR Hot-Rodding

[D1028Gary@xxxxxxx]

Hello All,
 
     After several requests to develop an alignment  system for the popular, 
compact Sony ICF-SW7600GR portable, I finally decided to  dig in to the 
circuitry, and investigate the stock loopstick thoroughly.   Perhaps the fact that 
an upcoming family vacation (during which our compact  vehicle would not 
accommodate the 30" or 19" loopstick modified  ICF-2010's) had something to do with 
my motivation.
 
     The SW7600GR loopstick is in fact a smaller  version of that used in the 
ICF-2010, i.e. a large, fixed center coil and a much  smaller end coil, used 
(in Sony's design) for adjusting the spurious signal  rejection of the 
loopstick. Like the ICF-2010 system,  there is no way to  align the fixed coils on 
this antenna.  The only way to significantly  improve AM-DX performance is to 
remove the entire 4 3/4" x 3/8" stock loopstick,  and replace it with a longer 
externally-mounted looptick having comparable  coil inductances. Fortunately, 
the ICF-2010 "Supercharging" file (currently  posted in dxer.ca's Ultralight 
File section) tells exactly how to accomplish  this, in an electrical manner.
 
     For the ICF-SW7600GR, a hobbyist will need to  measure the stock 
inductances of the two coils, and either recycle the stock  loopstick in a larger 
composite bar augmented by blank 3/8" ferrite bars on the  ends, or create a 
self-wound loopstick on 1/2" diameter Amidon ferrite bars (my  probable choice).  
Practically speaking, the external loopstick should be  limited to a length of 
about 15", since it is unlikely that this hot-rodded  SW7600GR would have a 
performance surpassing that of a hot-rodded ICF-2010, even  with a longer 
loopstick.
 
     It will be interesting to see how this  "supercharged" ICF-SW7600GR 
performs in the real world.  Although not  really close to being an "Ultralight" 
radio, it might be useful as a barebones  SSB "spotting receiver" for those 
travelers unable to accommodate a more capable  SSB unit.
 
73, Gary DeBock   



**************Get the scoop on last night's hottest shows and the live music 
scene in your area - Check out TourTracker.com!      
(http://www.tourtracker.com?NCID=aolmus00050000000112)
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx